Apparently the more you cough, the more you cough because its a reflex.  My husband has lung cancer and I give him small fruity drops to suck, this stops the cough reflex and soothes his throat and stops him thinking about coughing !  The chemist sells these drop sweets in small boxes so you can put them in your pocket or in the car or anywhere else you want.  I hope this helps a little bit.  People have good advice on this f becweve all been through it!  Carol